1. Field of the Invention
Aspects of the present invention relate to a fuel composition for a fuel cell and a fuel cell using the same. More particularly, aspects of the present invention relate to a fuel composition containing additives that increase catalytic activity so as to maximize the performance of a fuel cell and a fuel cell using the same.
2. Description of the Related Art
Methanol in direct methanol fuel cells (DMFCs) is adsorbed by an anode catalyst and reacts as indicated by Reaction Scheme 1 below to produce electrons, protons, and carbon monoxide.

The carbon monoxide produced through this reaction can attach to the anode catalyst and cause the area of the catalyst where oxidation occurs to decrease, thereby reducing the power output of the fuel cell. To overcome this problem, a method of using an anode catalyst that promotes additional oxidation of CO and a method of using a mixture of methanol and an aqueous liquid electrolyte as a fuel have been suggested. According to such methods, methanol reacts with water at the anode as indicated by Reaction Scheme 2 to produce carbon dioxide, electrons and protons.

In DMFCs, a solid polymer electrolyte membrane is used as an electrolyte membrane. The solid polymer electrolyte membrane may be a perfluorocarbon membrane such as a Nafion® membrane. However, when such a solid polymer electrolyte membrane is used, methanol diffuses through the electrolyte membrane, and thus, a large amount of methanol for generating electricity cannot be used and is lost by evaporation. Also, when methanol contacts the cathode catalyst, the methanol is directly oxidized on the cathode and generates heat instead of electricity, thereby reducing the amount of current generated. Moreover, protons generated at the anode catalyst layer cannot smoothly move to the cathode catalyst layer by passing through the solid polymer electrolyte membrane, thereby reducing the amount of current generated.
In order to overcome these problems, it has been suggested to actively produce hydroxide ions (OH−) in a DMFC or in a fuel cell that uses NaBH4 as fuel by including a compound such as Na2S2O3, Na2HPO3, or Na2HPO2 in the fuel cell (U.S. Pat. No. 6,773,470).
However, the performance of such a fuel cell has not yet reached a satisfactory level, and, thus, there is much to be improved.